Paper-making- machine



New. 4, 1924. 1,514,556

7 v 1.1.1:. MILKEY PAPER MAKING IACHINE' "PARTICULARLY ADAPTED TO MAKINGTISSUE AND OTHER THIN PAPERS -Filed March 25. 19225 2 Sheets-6h! 1 ll lll Nov. 4 1924. 1,514,556

E. MILKEY L. PAPER MAKING MACHINE, PARTICULARLY ADAPTED TO MAKING TISSUEAND OTHER THIN PAPERS Filed March- 26, 1923 Sheets-Sheet 2ZemerZC/Vilkgy.

Patented Nov. 4, 1924.

UNITED STATES PATENT OFFICE;

Ems n. Imam or sANnnsKY, onto.

i fii iiin-itiiiizine madman, renrxonnnnrrn iilrrun To MAKING 'rIsslrirE AND I I OTHER THIN r'ArERs.

t pnct an filed March 26, 1923. $eria1 no. 627,902.

To, all whom it may ooncemifl Be it known that 'I, Liesrnn ERNESTMri'lniir, a citizen of the United States, residing-at S'andusky, in thecounty of Erie and State of Ohio, have invented a new and useful Papersraking Machine, Partic ulaifly j A'daptedi to Making Tissue and OtherThin Papers, of which the followingis P 1 61 "tha a: a a

,iiivehtioii relates to an improved pa t erhnaking machine it is myobject to provide a niachihe so constructed and arranged as to beparticularlv adapted to makingtissue and other thin papers; and toprovide a paper-making machine in which theweb 'of paper continuouslysupported or carried from the time it is formed until it passes throughthe first press rolls and reaches a dry enough condition tosupportitself in its further passage through the paper-making machine Iattainthese and other ob ects of my inventlon by the mechanism illustrated inthe accompanying drawings,in. Which a I Figure l is one form'of myinvention and Fig. 2 is another form of my invention incorporating adevice which I have heretofore patented No. 1;387,061. A Y

Like numerals designate like parts in each of the views; 1

Referring to the accompanying drawings I provide a tank 1 containing asupply of pulp 2whicli is fed bn the endlessscreen 3, this screen 3trayersing a drum 4:, asuotio'n roll 5 and idle rollers 6, as shown inFig. 1. I provide a suction box 7 underneath screeii 3 to draw water outof the pulp. I

further provide aI n1et'al upper press roll'8" in operative contact withthe wire screen unde 'r'o'll SI provide the lower press roll 9 having arubber cover'ed surface 10 Over whichtravelsthe endless p felt 11! thisfelt beiiig guided ever the suitably arranged felt rollers 12. I providea suitable suctioii lio'ii 13 forthe endless-press felt 11, as shown inboth" figures. I provide, a drip pan 14 Positioned above the metal upperpress roll 8 I may provide a doctor blade 15 for the, purpose of crepingthe paper.

3 is supported.

I provide a paper carrying roll "21 in proX- imity to the metal upperpress roll 8.,to receive the paper as it passes over that roll and Ialso provide a conventional or baby dryer roll 16 beyond the papercarrying roll 21 I further provide the standard first dryer 17 andendless dryerfelt 18 passing over the felt rolls l9. I provide asuitable blow pipe 20 in proximity to the metal upper press roll 8-andto one of the idle rollers 6 to loosen the paperfrom the wiret screen 3so that it will pass around the roll 8 as indicated in the drawings.\Vhile I may use the air blast to loosen the sheet in start.- ing up themachine, in most cases I do not need it or use it at all, for the smoothsur-. face of the press roll has a greater aflinity for the paper webthan has the wire screen. Therefore, the paper web clings to and fol-.lows the surface of the press roll andina smooth flat condition withoutwrinkles or bubbles. "With thearrangement disclosed the paper web doesnot remaihunsupported at any time and therefore cannot break, as ispossible with the machines of the prior Referring to Fig. 20f thedrawings, there are illustrated suitable d'eckles22 on opposite sides ofthe rollers 23 toconfine the flowing pulp and 'sodetermine the width ofthe paper. In this form of the invention the l wirejscreentravcls over abreast roll. 24 and the idle rollers 25. I provide a plurality of idlesupporting rollers 25, spaced a suit able distance apart, on which thewire screen I prefer to provide also the revolving blow roll 26 which Ihave heretofore patented and also I provide a suitable drip pan 27beneath the revolving blow roll 26 As indicated in beta Figures "1' as.2, 2e

indicates the point Where th'epulp is fed onto the Wire screen 3; 29indicates the point where the paper leaves the wire screen 3 andpasses-part way round the metal upper press roll 8, leaving thatelementat the oint 30 where it passes to the paper carrymg roll 21 andthence aroundthe conventional or baby dryer roll 16, and thence into Ithe standard first dryer 17.

It is Well known that paper making maof paper frequently and easilybreaks on account of its strength not being sufficient to carry itselffrom one to the other unsupported. In attempts to overcome this someadaptations of the regular Fourdrinler a er makinq'machine have beenmade p 2 In these as in the others, the moist web f paper is picked orcouched off from the wire screen by a first press top or bottom feltwhich, through the use of a couch or press roll, is made to come lntocontact with and press against the wire screen with the web of paperbetween. This felt picks up the web of paper and'then carries it throughthe first-press rolls. This method has several serious disadvantageswhich limits its use ver 7 much.- One of them is that the picking offfelt absorbs considerable water during its contact with the wet wirescreen and paper web and it then becomes extremely difficult if notimpossible to use enough pressure between the press rolls to obtain therequireddryness of the paper web or sheet without crushing thelatter-due to the large quantity of water already carried by the feltitself, The felt when already very wet can not take up and absorb theadditional water that ispressed from the paper web by the actionof thepress rolls and consequently the paper web suffers what is known to thetrade as crushing. Moreover, the felt under these conditions, rapidlyfills up and becomes dirty and in order to be useful at all, re-' quiresconstant and severe washing and beating, all of which is detrimental tothe life of the felt. On some of these machines the felts last only afew days indicating the great expense involved.

Another disadvantage to this'arrangement is that the felts must be madeof a character suitable .for picking 'up the web of paper.

And to do this requires that thosecharacteristics of the felt which arebest suited for the primary purpose of absorbing the water as it ispressed out of the paper web by the tained Water, is then transferreddirectly onto the non-absorbing and bare surface of the upper press rollby causing the same Wire screen upon which the paper is formed, to bearagainst a part of the circumference of the upper press roll as shown.The smooth surface of the press roll, ordinarily made of metal, hasgreater affinity for the moist paper web than has the wire screen, andthe paper web or sheet therefore adheres to the metal roll and isautomatically carried along with it and then between the first pressfelt and the upper press roll to be pressed at the bite or pinch of thepress rolls in the orthodox way.

Sometimes when this paper machine is started up or when making certaingrades of paper it is desirable to use a blast to gently free the paperweb from the wire screen just as the latter makes or departs from itscontact with the upper press roll. This is indicated on the drawing. Theupper press roll is also in some instances steam heated for the purposeof still further caus ing the moist paper to transfer to and to adhereto it. Heating the top press roll serves the further purpose of warmingup the moist paper in which condition it gives up its water more readilywhile being pressed.

From the surfaceof the upper press roll and after having passed throughthe press rolls, the web of paper is then sufficiently dry to supportitself and is led over rolls as shown and usually into the'dryers as onan ordinary paper machine. Or if it is desired to produce a crped paper,a doctor blade is used as shown to scrape the paper sheet free from thesurface of the upper press roll.

The formation of the paper web itself may take place in any of severalways, two of which are shown by the drawings. In any case, however, thepaper web is formed on an endless wire screen.

With my invention the first press felt has no opportunity to absorbwater except that pressed out of the paper as it passes through the biteof the pressrolls and this is the primary and all important purpose ofany paper machine press felt. The felt does not, therefore, need to bespecially made or napped to give it the picking up qualities sonecessary on present machines of the Harper or similar type, but can bebest made to ful; fill its single purpose of absorbing water at thepressing operation by the press rolls, The press felt thus has greaterlength of life and does not require constant and destructive washinAnother advantage of my invention is that the paper itself is pressedmuch drier so that it can be handled at that point on the machine withvery little danger of breaking. And the paper being drier, less steam isnecessary to finish drying it. Prior to the pressing operation, thepaper web cannot a CD break regardless of the voperating speed of themachine and what is known asthe wet end of the paper, making machinethenbecomes largely auttnnati'c. Inother words I have provided a papeiumaking machinev in which the recognized advantages of forming a web ofpaper on an endless wire screen can be utilized iii. making very thinpapers because of the elimination of the usual gap between the wirescreen and the first press felt on such machines which the paper mustspan unsupported. And this is accomplished without bringing the feltitself into contact with the wire screen just mentioned.

The upper metal press roll may be either steam or otherwise suitablyheated or a cold roll, and the diagrammatic illustration is in tended toinclude the disclosure of either a cold roll or a heated roll, havingsuitable and appropriate means for heating same.

What I claim is:

1. In a paper making machine, the combination of a pair of engagingpress rolls of the conventional type, and means sup porting and directlytransferring the newly formed web of paper on to the bare surface of theupper press roll from the endless wire screen upon which the paper webwas formed.

2. In a paper making machine, the con bination of an endless wire meshscreen upon which the paper web is formed, a pair of engaging pressrolls and means for bringing said wire screen with the moist paper webon it into contact with the bare surface of the upper press roll priorto its being pressed or squeezed in the conventional way.

3. In a paper making machine, the combination of a pair of engagingpress rolls, an endless felt or apron passing around .the lower one ofsaid press rolls, means for sup porting and transferring the moist webof paper from the endless wire screen upon which it was independentlyand previously formed directly on to the surface of the upper press rollprior to its passing through the bite of the press rolls.

4. In a paper making machine, the oombination of a pair of engagingpress rolls, an

endless felt or apron passing around the lower one of said press rolls,means for directly transferring the moist web of paper from the endlesswire screen upon which it was independently formed to the bare surfaceof the upper press roll by bringing said wire screen into contact withsaid upper press roll, substantially as shown.

5. In a paper making machine, the conr bination of an endless wirescreen upon which the paper web is formed and by which it is supported,a pair of engaging press rolls, one of said rolls being in operativecontact with the endless wire screen, means for directing an air-blastthrough the wire screen at a point where it separates from the pressroll with which it contacts to l v the paper web from the wire,screen-and transfer it directly to the baresurface of the press rolls,substantially asshown.

6. In a paper making inacl'iine, the com;

bin-ation of an endless wire screen .upon which the; paper web is formedand, by. which it is supported, a pair of engaging press rolls, theupper press roll being heated, one of said rolls being in operativecontact with the endless wire screen, means for olirecting an air-blastthrough the wire screen at a point where it separates from the pressroll with which it contacts to loosen the paper web from the wire screenand transfer it directly to the bare surface of the press rolls,substantially as shown.

7. In a paper making machine, the co1nb? tion of an endless wire screenupon which the paper web is formed and by which it is supported, a pairof engaging press rolls with one of which the endless wire screencontacts, and to which the paper is directly transferred, an endlessfelt engaging around the lowerv press roll and in contact with the upperpress roll, and means for extracting moisture from the endless pressfelt prior to its passing into the bite of the press rolls.

8:111 a paper making machine the combination of an endless wire screenupon which the paper web is formed, a pair of engaging press rolls, theendless wire screen being arranged to support the paper and transfer itdirectly to the upper press roll, the ripperpress roll being heated, anda doctor blade in operative engagement with the upper press roll forcrping the paper on the heated upper press roll.

9. In a paper making machine, the combination of a pair of engagingpress rolls, an endless wire screen uponwhich the moist paper web isformed, said endless wire screen carrying the moist paper web intodirect contact with a portion of the surface of the upper press roll,means for directing a blast of air through the screen at the point whereits contact with the upper press roll ends to cause the paper to adhereto the upper press roll, endless press felt extending around the lowerpress roll, means for extracting moisture from said endless press feltprior to its passing throughthe bite of the press rolls, a papercarrying roll positioned in proximity to the upper press roll at theopposite side from the endless wire screen for guiding it to the driermechanism of the machine.

10. In a paper making machine, the combination of a pair of engagingpress rolls,

an endless wire screen upon which the moist liS tion of the surface ofthe press r011 means for extracting moisture from the paper web as itpasses over the endless wire screen prior to its contact with the upperpress roll,

' means'for directing a blast of air through the screen at the pointWhere its contact with the upper press roll ends to cause the paper toadhere to the upper press roll, an endless press felt extending aroundthe lower press roller, means for extracting moisture from 1 the endlesswire screen for guiding it to the 15 drier mechanism of the machine.

LESTER E. MILKEY.

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